1. Field of the Invention
This invention relates to a slide fastener, and more particularly to a fastener stringer having a continuous plastic filament spirally formed and woven into an edge of a stringer tape during the weaving thereof.
2. Prior Art
There have been proposed a number of slide fasteners or zippers of the type described, which comprise a woven stringer tape and a plastic filament woven into a longitudinal edge of the tape, the filament being usually formed into a helical coil structure consisting of a row of successive elongated loops or convolutions each having a coupling head, an upper and a lower leg and a connecting portion.
Most of the known fasteners, however, have failed to meet with the requirements for the success of the so-called woven slide fasteners which largely depends on one hand, upon the positional stability of the filament, i.e. coupling fastener element, with respect to the stringer tape against external stresses, and on the other hand, upon smooth coupling and uncoupling of the opposed stringer by the action of a reciprocating slider.
A woven slide fastener was proposed in Japanese Patent Application No. 53-91 wherein a stuffing cord is inserted longitudinally through the coil of the filament and a guide cord or cords is disposed longitudinally of the filament in contact with the connecting heel portions of the coupling filament loops, the stuffing and guide cords being bound integrally with the coupling filament by the weave threads of the tape.